Mechanical Engineering / Makina Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4129
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Conference Object Redundancy resolution options for the twin-it-romans robotic hybrid manufacturing system(Springer Science and Business Media B.V., 2025) Gündüz, G.M.; Dede, Mehmet İsmet Can; Kiper, Gökhan; Schmitz, M.; Corves, B.The Twinnig Iztech in Robotics Manufacturing System (TWIN-IT-ROMANS) project funded by EU Horizon -Widera-2023-Access-02-01 aims to develop a hybrid manufacturing system that can perform additive and subtractive manufacturing processes and inline quality control using a robotic system. The system will incorporate a 6-degree-of-freedom robot arm and a positioner with 2-degree-of-freedom, which will operate synchronously. This manipulation system is to be designed for performing different manufacturing operations with different degrees-of-freedom requirements. In order to reveal alternative trajectory planning scenarios for this system, this paper presents an initial review of redundancy resolution approaches for kinematically redundant robotic manipulators. First, the four main approaches for redundancy resolution techniques are introduced. Then main studies on energy minimization and stiffness maximization for kinematically redundant robotic manipulators are reviewed. Similar or new approaches are planned to be generated and implemented for the redundant system for hybrid manufacturing. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.Article Citation - WoS: 10Citation - Scopus: 12A Robot Arm Design Optimization Method by Using a Kinematic Redundancy Resolution Technique(MDPI, 2022) Maaroof, Omar W.; Dede, Mehmet İsmet Can; Aydın, LeventRedundancy resolution techniques have been widely used for the control of kinematically redundant robots. In this work, one of the redundancy resolution techniques is employed in the mechanical design optimization of a robot arm. Although the robot arm is non-redundant, the proposed method modifies robot arm kinematics by adding virtual joints to make the robot arm kinematically redundant. In the proposed method, a suitable objective function is selected to optimize the robot arm’s kinematic parameters by enhancing one or more performance indices. Then the robot arm’s end-effector is fixed at critical positions while the redundancy resolution algorithm moves its joints including the virtual joints because of the self-motion of a redundant robot. Hence, the optimum values of the virtual joints are determined, and the design of the robot arm is modified accordingly. An advantage of this method is the visualization of the changes in the manipulator’s structure during the optimization process. In this work, as a case study, a passive robotic arm that is used in a surgical robot system is considered and the task is defined as the determination of the optimum base location and the first link’s length. The results indicate the effectiveness of the proposed method.Conference Object Citation - Scopus: 2Experimental Compliance Matrix Derivation for Enhancing Trajectory Tracking of a 2-Dof High-Accelerated Over-Constrained Mechanism(Springer, 2022) Paksoy, Erkan; Dede, Mehmet İsmet Can; Kiper, GökhanIf the positioning accuracy of the end-effector of a robot has high priority, compliance characteristics of the elements of its mechanism should be considered. Due to the external loading on the robot, the dimensions of the elements change and this leads to positioning errors for the end-effector. In this paper, an experimental test setup and an experimental procedure are described to derive the compliance characteristics of a planar 2-degree-of-freedom mechanism.Article Citation - WoS: 7Citation - Scopus: 7Gravity Compensation of a 2r1t Mechanism With Remote Center of Motion for Minimally Invasive Transnasal Surgery Applications [article](Cambridge University Press, 2023) Aldanmaz, Ataol Behram; Ayit, Orhan; Kiper, Gökhan; Dede, Mehmet İsmet CanThis work addresses the gravity balancing of a 2R1T (2 rotations – 1 translation) mechanism with remote center of motion. A previously developed balancing solution is modified and applied to a prototype and test results are presented. The mechanism is an endoscope holder for minimally invasive transnasal pituitary gland surgery. In this surgery, the endoscope is inserted through a nostril of the patient through a natural path to the pituitary gland. During the surgery, it is vital for the manipulator to be statically balanced so that in case of a motor failure, the patient is protected against any harmful motion of the endoscope. Additionally, static balancing takes the gravitational load from the actuators and hence facilitates the control of the mechanism. The mechanism is a 2URRR-URR type parallel manipulator with three legs. The payload mass is distributed to the legs on the sides. By using counter-masses for two links of each leg, the center of mass of each leg is lumped on the proximal link which simplifies the problem to balancing of a two degree-of-freedom inverted pendulum. The two proximal links with the lumped mass are statically balanced via springs. Dynamic simulations indicate that when the mechanism is statically balanced, generated actuator torques are reduced by 93.5%. Finally, the balancing solution is implemented on the prototype of the manipulator. The tests indicate that the manipulator is statically balanced within its task space when the actuators are disconnected. When the actuators are connected, the torque requirements decrease by about 37.8% with balancing.Conference Object Haptik Cihaz için İyileştirilmiş Performansa Sahip Robot Tasarımı(Özyeğin Üniversitesi, 2019) Görgülü, İbrahimcan; Karabulut, Mehmet Görkem; Sekendiz, Veysel; Kiper, Gökhan; Dede, Mehmet İsmet CanBu bildiri daha önce tasarlanmış bir kinestetik haptik cihazın tasarımının iyileştirilmesi için yapılan çalışmayı içermektedir. Bahsi geçen iyileştirme cihazın empedans aralığının genişletilmesine yöneliktir. Bu başarım kıstasında iyileştirme için yapılan mekanizma eniyileme, pasif dengeleme, konstrüksiyonel tasarımda iyileştirme ve eyleyici sistem tasarımı çalışmaları yürütülmüş ve bu bildiride sunulmuştur.Conference Object Yüksek İvmeli Paralel Robotların Konumlama Hassasiyetinin Artırılmasına Yönelik Yöntemlerin Araştırılması(Makina Teorisi Derneği, 2019) Uzunoğlu, Emre; Özkahya, Merve; Paksoy, Erhan; Taner, Barış; Dede, Mehmet İsmet Can; Kiper, GökhanBu çalışmanın temel amacı endüstriyel uygulamalarda giderek sıkılıkla kullanılmaya başlanan yüksek ivmeli çalışan paralel robotların konumlama hassasiyetlerini artırmak üzere yapısal ve denetimsel iyileştirme yöntemlerinin araştırılmasıdır. Çalışma dâhilinde robot sistemlerinin hassasiyetini bozan geometrik olan ve olmayan faktörlerin etkilerinin en aza indirilmesi için yöntemler araştırılmıştır ve önerilmiştir. Bu yöntemler içerisinde geometrik olan faktörlerin tamamı, geometrik olmayan faktörlerden robot manipülatör direngenlikleri ve denetim hataları, ve bunlara ek olarak dengelenmemiş kütlelerden kaynaklanan hatalar konularında yapılan araştırmalar sunulmuştur. Ayrıca yöntemlerin araştırılması, kıyaslama amacı ile aynı işi yapmak üzere iki farklı yapıya sahip normal kısıtlı ve fazla kısıtlı iki mekanizma yapısı bu bildiri dâhilinde sunulmuştur.Conference Object Digital Twin of a Servo Driver of a Servo Motor as a First Step Towards a Digital Twin of a Robot Mechanism(Springer, 2022) Küçükoğlu, Sefa Furkan; Carbone, Giuseppe; Dede, Mehmet İsmet CanDigital Twin (DT) offers us to acquire actual system’s critical information and hence, it may be possible to develop and produce more suitable systems in terms of low energy consumption and effectiveness. In this way, responsible consumption and production systems can be designed and the system’s parameters can be tuned via DT. In this study, the model of a servomotor system that is used for industrial purposes is experimentally obtained. This study consists of two steps. In the first step, within the embedded control of the system, position and velocity control loops are deactivated. Then through the servo driver, currents with sinusoidal waveforms at various frequencies are applied to the servomotor. The resultant angular velocity of the motor is monitored and recorded. The amplitude of the current is kept constant during this study. The frequency of the current, however, is increased logarithmically. By using these data, a first-order transfer function (TF) is identified for the motor model. In the second step, all control loops are activated. Consequently, the total servomotor system could be represented in a digital environment. Furthermore, the static friction issue is overcome by using a Coulomb friction model with stiction effect. Finally, several experiments are conducted and then results are compared with the digital model of the servomotor system. The results clearly show that digital model can fairly represent the physical system.Book Part Citation - WoS: 1Citation - Scopus: 1Calibration Study of a Continuously Variable Transmission System Designed for Phri(Springer, 2020) Mobedi, Emir; Dede, Mehmet Ismet CanVariable stiffness actuators (VSAs) have been used in many applications of physical human-robot interfaces (pHRI). A commonly employed design is the spring-based VSA allowing the user to regulate the output force mechanically. The main design criteria of these actuation systems are the adjustment of output force independent from the output motion, and shock absorbing. In our recent work, we implemented certain modifications on the two-cone friction drive continuously variable transmission system (CVT) so that the CVT can be employed in pHRI systems. Subsequently, the optimized prototype is developed. In this study, we introduce the prototype of this new CVT systems, and its force calibration tests. The results indicate that the manufactured CVT is capable of displaying the desired output force throughout its transmission ratio range within a tolerance.Article Citation - WoS: 31Citation - Scopus: 37Kinematic Design of a Non-Parasitic 2r1t Parallel Mechanism With Remote Center of Motion To Be Used in Minimally Invasive Surgery Applications(Elsevier Ltd., 2020) Yaşır, Abdullah; Kiper, Gökhan; Dede, Mehmet İsmet CanIn minimally invasive surgery applications, the use of robotic manipulators is becoming more and more common to enhance the precision of the operations and post-operative processes. Such operations are often performed through an incision port (a pivot point) on the patient's body. Since the end-effector (the handled surgical tool) move about the pivot point, the manipulator has to move about a remote center of motion. In this study, a 3-degrees-of-freedom parallel mechanism with 2R1T (R: rotation, T: translation) remote center of motion capability is presented for minimally invasive surgery applications. First, its kinematic structure is introduced. Then, its kinematic analysis is carried out by using a simplified kinematic model which consists of three intersecting planes. Then the dimensional design is done for the desired workspace and a simulation test is carried out to verify the kinematic formulations. Finally, the prototype of the final design is presented.Article Citation - WoS: 11Citation - Scopus: 11A New Stiffness Performance Index: Volumetric Isotropy Index(MDPI, 2019) Görgülü, İbrahimcan; Dede, Mehmet İsmet CanA new index for a precise calculation of a manipulator's stiffness isotropy is introduced. The proposed index is compared with the conventionally used stiffness isotropy index by making use of the investigation on R-CUBE manipulator. The proposed index is shown to produce relatively more precise results from which a higher number of isotropic poses are detected.